Abstract
The existence of a quantum spin liquid (QSL) in which quantum fluctuations of spins are sufficiently strong to preclude spin ordering down to zero temperature was originally proposed theoretically more than 40 years ago, but its experimental realization turned out to be very elusive. Here we report on an almost ideal spin liquid state that appears to be realized by atomic-cluster spins on the triangular lattice of a charge-density wave state of 1T-TaS2. In this system, the charge excitations have a well-defined gap of ∼0.3 eV, while nuclear quadrupole resonance and muon-spin-relaxation experiments reveal that the spins show gapless QSL dynamics and no long-range magnetic order at least down to 70 mK. Canonical T2 power-law temperature dependence of the spin relaxation dynamics characteristic of a QSL is observed from 200 K to Tf = 55 K. Below this temperature, we observe a new gapless state with reduced density of spin excitations and high degree of local disorder signifying new quantum spin order emerging from the QSL.
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References
Anderson, P. W. Resonating valence bonds: a new kind of insulator? Mater. Res. Bull. 8, 153–160 (1973).
Balents, L. Spin liquids in frustrated magnets. Nature 464, 199–208 (2010).
Shen, Y. et al. Evidence for a spinon Fermi surface in a triangular-lattice quantum-spin-liquid candidate. Nature 540, 559–562 (2016).
Paddison, J. A. M. et al. Continuous excitations of the triangular-lattice quantum spin liquid YbMgGaO4 . Nat. Phys. 13, 117–122 (2017).
Itou, T., Oyamada, A., Maegawa, S. & Kato, R. Instability of a quantum spin liquid in an organic triangular-lattice antiferromagnet. Nat. Phys. 6, 673–676 (2010).
Pratt, F. L. et al. Magnetic and non-magnetic phases of a quantum spin liquid. Nature 471, 612–616 (2011).
Rossnagel, K. On the origin of charge-density waves in select layered transition-metal dichalcogenides. J. Phys. Condens. Matter 23, 213001 (2011).
Huse, D. A. & Elser, V. Simple variational wave functions for two-dimensional Heisenberg spin-1/2 antiferromagnets. Phys. Rev. Lett. 60, 2531–2534 (1988).
White, S. R. & Chernyshev, A. L. Neél order in square and triangular lattice Heisenberg models. Phys. Rev. Lett. 99, 127004 (2007).
Stojchevska, L. et al. Ultrafast switching to a stable hidden quantum state in an electronic crystal. Science 344, 177–180 (2014).
Yoshida, M., Suzuki, R., Zhang, Y., Nakano, M. & Iwasa, Y. Memristive phase switching in two-dimensional 1T-TaS2 crystals. Sci. Adv. 1, e1500606 (2015).
Vaskivskyi, I. et al. Fast electronic resistance switching involving hidden charge density wave states. Nat. Commun. 7, 11442 (2016).
Hellmann, S. et al. Time-domain classification of charge-density-wave insulators. Nat. Commun. 3, 1069 (2012).
Fazekas, P. & Tosatti, E. Electrical, structural and magnetic properties of pure and doped 1T-TaS2 . Philos. Mag. B 39, 229–244 (1979).
Perfetti, L., Gloor, T. A., Mila, F., Berger, H. & Grioni, M. Unexpected periodicity in the quasi-two-dimensional Mott insulator 1T-TaS2 revealed by angle-resolved photoemission. Phys. Rev. B 71, 153101 (2005).
Gasparov, L. V. et al. Phonon anomaly at the charge ordering transition in 1T-TaS2 . Phys. Rev. B 66, 094301 (2002).
Ma, L. et al. A metallic mosaic phase and the origin of Mott-insulating state in 1T-TaS2 . Nat. Commun. 7, 10956 (2016).
Cho, D. et al. Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2 . Nat. Commun. 7, 10453 (2016).
Svetin, D., Vaskivskyi, I., Brazovskii, S. & Mihailovič, D. Three-dimensional resistivity switching between correlated electronic states in 1T-TaS2 . Sci. Rep. 7, 46048 (2017).
Lee, S.-S. & Lee, P. A. U(1) gauge theory of the Hubbard model: spin liquid states and possible application to κ − (BEDT − TTF)2Cu2(CN)3 . Phys. Rev. Lett. 95, 036403 (2005).
Motrunich, O. I. Variational study of triangular lattice spin-1/2 model with ring exchanges and spin liquid state in κ − (ET)2Cu2(CN)3 . Phys. Rev. B 72, 045105 (2005).
Yaouanc, A. & de Rotier, P. D. Muon Spin Rotation, Relaxation, and Resonance (Oxford Univ. Press, 2010).
Naito, M., Nishihara, H. & Tanaka, S. Nuclear quadrupole resonance in the charge density wave state of 1T-TaS2 . J. Phys. Soc. Jpn 53, 1610–1613 (1984).
Naito, M., Nishihara, H. & Tanaka, S. Nuclear magnetic resonance and nuclear quadrupole resonance study of 181Ta in the commensurate charge density wave state of 1T-TaS2 . J. Phys. Soc. Jpn 55, 2410–2421 (1986).
Torgeson, D. R. & Borsa, F. Temperature dependence of the electric field gradient in a quasi-two-dimensional metal: NbSe2 . Phys. Rev. Lett. 37, 956–959 (1976).
Darancet, P., Millis, A. J. & Marianetti, C. A. Three-dimensional metallic and two-dimensional insulating behavior in octahedral tantalum dichalcogenides. Phys. Rev. B 90, 045134 (2014).
Kaneko, R., Morita, S. & Imada, M. Gapless spin-liquid phase in an extended spin 1/2 triangular Heisenberg model. J. Phys. Soc. Jpn 83, 093707 (2014).
Walstedt, R. E. Spin-lattice relaxation of nuclear spin echoes in metals. Phys. Rev. Lett. 19, 146–149 (1967).
Khuntia, P., Kumar, R., Mahajan, A. V., Baenitz, M. & Furukawa, Y. Spin liquid state in the disordered triangular lattice Sc2Ga2CuO7 revealed by NMR. Phys. Rev. B 93, 140408 (2016).
Shiroka, T. et al. Distribution of NMR relaxations in a random Heisenberg chain. Phys. Rev. Lett. 106, 137202 (2011).
Fisher, D. S. Random antiferromagnetic quantum spin chains. Phys. Rev. B 50, 3799–3821 (1994).
Klanjšek, M. et al. Controlling Luttinger liquid physics in spin ladders under a magnetic field. Phys. Rev. Lett. 101, 137207 (2008).
Klanjšek, M. et al. Phonon-modulated magnetic interactions and spin Tomonaga-Luttinger liquid in the p-orbital antiferromagnet CsO2 . Phys. Rev. Lett. 115, 057205 (2015).
Uchida, S., Tanabe, K. & Tanaka, S. Nonlinear conduction in two-dimensional CDW system: 1T-TaS2 . Solid State Commun. 27, 637 (1978).
Bain, G. A. & Berry, J. F. Diamagnetic corrections and Pascal’s constants. J. Chem. Educ. 85, 532–536 (2008).
DiSalvo, F. J. & Waszczak, J. V. Paramagnetic moments and localization in 1T-TaS2 . Phys. Rev. B 22, 4241–4246 (1980).
Ganal, P., Butz, T., Lerf, A., Naito, M. & Nishiharad, H. The 181Ta nuclear quadrupole interaction in the charge density wave phases of 1T-TaS2 . Z. Nat. forsch. 45a, 439–444 (1990).
Chepin, J. & Ross, J. H. Magnetic spin-lattice relaxation in nuclear quadrupole resonance: the eta not=0 case. J. Phys. Condens. Matter 3, 8103–8112 (1991).
Abragam, A. Principles of Nuclear Magnetism (Oxford Univ. Press, 2011).
Wilson, J., Salvo, F. D. & Mahajan, S. Charge-density waves and superlattices in the metallic layered transition metal dichalcogenides. Adv. Phys. 24, 117–201 (1975).
Acknowledgements
The authors acknowledge fruitful discussions with P. Carretta. The authors also acknowledge the contribution of P. Šutar in sample preparation and structural characterization. D.A. acknowledges the financial support by the Slovenian Research Agency, grant No. N1-0052; D.M. acknowledges funding by the ERC AdG Trajectory.
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D.A., D.M. and P.P. conceived and designed the project and directed and coordinated the research. M.K., A.Z. and P.K.B. performed the μ+SR experiments and analysed the data. M.K. and A.Z. carried out NQR measurements and analysed the data. Z.J. measured spin susceptibility and together with D.A. analysed the data. All authors discussed the results. D.A. wrote the paper with input from all authors.
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Klanjšek, M., Zorko, A., Žitko, R. et al. A high-temperature quantum spin liquid with polaron spins. Nature Phys 13, 1130–1134 (2017). https://doi.org/10.1038/nphys4212
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DOI: https://doi.org/10.1038/nphys4212
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